Wireless spectrum has historically been allocated in a fixed manner. For example, a government agency may allocate a particular frequency band to a particular TV channel in a particular city while prohibiting others from using that band in that city. This fixed allocation typically persists until another allocation is made.
Now some wireless spectrum is being made available for wireless communications using temporary location-based allocations. That is, this spectrum will be assigned by request based on the location of the requesting wireless device. This type of spectrum is often referred to as “white space.” For example, the broadcast TV channels that became available with the switch from analog to digital TV broadcasting are often referred to as “TV white space.” TV white space offers much higher bandwidth than Wi-Fi, and is expected to support “smart appliances” and other smart devices that communicate over white space channels. For example, a user might employ white space channels to remotely monitor and control appliances such as TV sets, hot water heaters, and the like.
FIG. 1 illustrates a conventional white space allocation process. Referring to FIG. 1, a wireless device 102 determines its location using GPS signals 104, and then sends a request 106 for white space allocation to a spectrum allocation server 108, for example over a wide-area network (WAN) 110 such as the Internet. Request 106 includes the location of wireless device 102. At 112, server 108 consults a spectrum allocation database 114 to obtain an available frequency band (also referred to herein as a “channel”) based on the location of wireless device 102. At 116 server 108 allocates the white space channel to wireless device 102. Wireless device 102 can then communicate wirelessly over the allocated white space channel at 118.
In the conventional location-based wireless spectrum allocation of FIG. 1, wireless device 102 must determine its location. FCC regulations for television white space mandate that Mode II devices have geolocation capabilities such as GPS receivers for this purpose. However, not all devices that could utilize white space will have such geolocation capabilities. It may be too expensive to place GPS receivers in cost-sensitive consumer devices that are not mobile. For example, a television set is stationary and would not normally be built with GPS facilities. Adding a GPS receiver to a television set is too expensive just to enable white space usage. In addition, an indoor device such as a television set may be shielded from GPS satellites, and so the television set would be unable to obtain its location.
Alternatively, FCC regulations require fixed devices be “professionally installed” where a licensed installer configures the location in the wireless device 102. However, this method is very expensive, and does not allow any movement of the wireless device, even from one room to another.